//: interfaces/Factories.java
package interfaces;

import static net.mindview.util.Print.*;

interface Service
{
    void method1();
    
    void method2();
}

interface ServiceFactory
{
    Service getService();
}

class Implementation1 implements Service
{
    Implementation1()
    {
    } // Package access
    
    public void method1()
    {
        print("Implementation1 method1");
    }
    
    public void method2()
    {
        print("Implementation1 method2");
    }
}

class Implementation1Factory implements ServiceFactory
{
    public Service getService()
    {
        return new Implementation1();
    }
}

class Implementation2 implements Service
{
    Implementation2()
    {
    } // Package access
    
    public void method1()
    {
        print("Implementation2 method1");
    }
    
    public void method2()
    {
        print("Implementation2 method2");
    }
}

class Implementation2Factory implements ServiceFactory
{
    public Service getService()
    {
        return new Implementation2();
    }
}

public class Factories
{
    public static void serviceConsumer(ServiceFactory fact)
    {
        Service s = fact.getService();
        s.method1();
        s.method2();
    }
    
    public static void main(String[] args)
    {
        serviceConsumer(new Implementation1Factory());
        // Implementations are completely interchangeable:
        serviceConsumer(new Implementation2Factory());
    }
} /*
   * Output:
   * Implementation1 method1
   * Implementation1 method2
   * Implementation2 method1
   * Implementation2 method2
   */// :~
